9.6.1 The Clipboard Selection

There are other kinds of X selections besides the Primary selection; one common one is the Clipboard selection. Some applications prefer to transfer data using this selection in preference to the Primary. One can transfer text from the Primary selection to the Clipboard selection with the Copy command under the Edit menu in the menubar.

Usually, the clipboard selection is not visible. However, if you run the xclipboard application, the text most recently copied to the clipboard (with the Copy command) is displayed in a window. Any time new text is thus copied, the xclipboard application makes a copy of it and displays it in its window. The value of the clipboard can survive the lifetime of the running Emacs process. The xclipboard man page provides more details.

Warning: If you use the xclipboard application, remember that it maintains a list of all things that have been pasted to the clipboard (that is, copied with the Copy command). If you don’t manually delete elements from this list by clicking on the Delete button in the xclipboard window, the clipboard will eventually consume a lot of memory.

In summary, some X applications (such as xterm) allow one to paste text in them from SXEmacs in the following way:

• Drag out a region of text in Emacs with the left mouse button, making that text be the Primary selection.
• Click the middle button in the other application, pasting the Primary selection.

With some other applications (notably, the OpenWindows and Motif tools) you must use this method instead:

• Drag out a region of text in Emacs with the left mouse button, making that text be the Primary selection.
• Copy the selected text to the Clipboard selection by selecting the Copy menu item from the Edit menu, or by hitting the Copy key on your keyboard.
• Paste the text in the other application by selecting Paste from its menu, or by hitting the Paste key on your keyboard.